Automatic retaining valve for air brakes



June 1 1926.

J. L. FARM ER AUTOMATIC RETAINING VALVE FOR AIR BRAKES Filed June 9,1925 INVENTOR J LIA RMER BY Vi ATTdRNEYs Patented June 1, 1926 PATENTOFFICE.

JOHN Lno' mm/ma, or onroaeo, ILLINOIS.

AUTOMATIC RETAINING VALVE FOR AIR BRAKES.

Application filed. June 9, 1925. Serial No. 36,006.

Myjinvention relates to improvements in automatic retaining valves forair brakes, and it consists in the combinations, constructions, andarrangements herein described and claimed.

An object of my invention is to provide an automatic air retaining valvefor air brakes which will permit the air from the brake cylinders toexhaust slowly when the engineer moves the brake lever in the engine cabso as to release the brakes and to cause the pumps on the locomotive toagain fill the compressed air tank on the locomotive and the compressedair tanks beneath each car. This slow exhaust of the air from the brakecylinder gives the pumps ample time to fill the various compressed airtanks.

I have found that wheretrains are descending a long grade, the air inthe compressed air tanks is exhausted to such an extent that there isnot suiiicient air in the brake cylinders to a the engineer so wishes.This is due to the fact that it takes a certain length of time to againbuild up the pressure within the compressed air tanks carried by thecars, and it the brakes have to be set during this time there will notbe sufficient air to applythe brakes and slow down the train. My devicepermits the air from the brake cylinders to exhaust slowly, thus keepingthe brakes partially applied while permitting the cylinders beneath thecars to be recharged with air. It will therefore be seen that it thebrakes have to be applied during the recharging of the auxiliary tankscarried by the cars, a small amount of air will set the brakes becausethe brake cylinders already have a certain amount of air therein.

A further object of my invention is to provide a device of the typedescribed which has adjustable means for permitting the rapid exhaust ofair from the brake cylinder above a certain number of pounds pressure,and then for slowly exhausting the rei'naining quantity of air in thecylinder so as to slowly release the brakes, thus giving the pumps ampletime to recharge the auxiliary tanks disposed beneath the cars. A

A further object of my invention is to provide a device of the characterdescribed which is simple in construction, durable and thoroughlypractical for the purposes intended.

gain set the brakes if Other objects and advantages will appear in thefollowing specification, and the novel ieatures of the invention will beparticularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawings, forming partof this apphcation,in Which- Figure l is a top plan view ofan embodimentof my invention,-

Figure 2 is a sectional 2 2 of Figure 1, I

Figure 3 is a sectional view along the line 3-3 of Figure 2, and

Figure 4 is a fragmentary sectional View of the mechanism as illustratedin Figure 2 in an operative position.

My automatic retaining valve for air brakes isintended for dispositiondirectlv on the exhaust port of the standard triple valve employed inthe ordinary type 01 air brakes for railroad cars and locomotives.

Ordinarily air is permitted to exhaust from the triple valve directlythrough the exhaust port so as to release the brakes. This exhaust ofair is very rapid and quickly releases the brakes. It sometimes happensthat the air within the auxiliary tanks beneath the cars is not of therequired pressure, and therefore if the engineer again wishes to applythe brakes, the brakes will not seat properly due to the fact that thereis not sufficient pressure in the auxiliary tanks to apply the brakes.\Vith my device view along the line I permit the slow exhaust of airfrom the brake cylinders, andi'f therefore the engineer again wishes toapply the brakes, he

can do so because it takes-a small quantity of additional air to againset the brakes.

In carrying out my invention, 1 provide a valve body member comprisingtwo parts A and B. The member A is substantially cylindrical in form andis secured to the member B by the projection of bolts 1 through alignedopenings 2 in radially projection portions 3 of the parts A and Brespectively. Nuts-4 are disposed upon the bolts 1 so as to draw theparts A and B into close engagement wit-hone another.

The part A has an enlarged portion 5 of the central bore 6 at the mouththereof into whicha bossed portion 7 of the part B is received. The partB is provided with an upwardly extending, exteriorly threaded neckportion 8 which has a passage 9 extil) ltll) tending longitudinallytherethrough and communicating at its lowermost end with the interior ofthe part A. h

A piston valve 10 is slid-ably disposed in the central bore 6 of themember A and closely engages the side walls thereof. The body member Ahas an 'inteiiorly threaded portion 11 at thelowernfiost endthereof inwhich a threaded plug 12 is received which may be moved longitudinallyupon rotation o'l' the plug as by engagement of a wrench or the likewith angular longitudinal projection 13 at the bottom of the plug. Alook nut 14 is provided on the plug 12 so as to lock the plug againstmovement relaiivc to the member A.

A compression spring 15 is disposed within the bore 5 of the mei-nbei' Abetween the plug 12 and the inner end of the piston valve 10. The pistonvalve 10, see Figure '3, has a recess 16 in the top wall thereof and isprovided with transverse grooves 17 across the uppermost portions of thepiston valve between the outer wall and the recess 16.

The outer peripheral upper edge of the piston valve 10 is beveled 'asshov'vn at 18. The member B has three passages 20 extendingtheretln'ough parallel with the axis or the bore '6 and at equaldistances from one another. The axes of the passages 20 lie slightlybeyond the walls of the bore The member A has bores 21 with their axesin registration with the @axes of the passages '20. The bores 21 extendinto the member A for a distance and communicate with the 'bore 6.

The body member A has a pair of exhaust ports 22 and 23 extendingtransversely through the side walls of the member, the port 22 beingabove the port 28. The 'body member A has a vent passage 2% therethroughbelow the lowermost end of the travel of the piston "valve '10. This'v-ent passage is for the purpose of preventing the compression of anbeneath the piston valve which might otherwise hinder the eflicientoperation of the device.

From the foregoing description of the various parts of the device, theoperation thereof may be readily understood. The device is attached tothe exhaust (port of the standard -triple valve found on all freightcars and passenger cars employed throughout the United States. Thisexhaust port is indicated in Figure 2 lIl'ClOlZtGCl lines the airbrakes. Normally the brakes will remain set as long as the air isreleased from the engineers line. hen the engineer has retarded thespeed of the train to what he thinks is a safe speed, he will move theair brake lever so as to move the triple valve to cause the valve topermit the air in the brake cylinder to exhaust and to connect theauxiliary tank in the car with the pumps for forcing additional air backinto the tanks. Without my device, the air would quickly exhaust fromthe brake cylinders and would therefore quickly release the brakes. Withmy device, the air will flow through the exhaust port 25 from the brakecylinder and will seep past the grooves 17, and the annular groove madeby the beveled edge 18 and the body member A, and thence to the otheroutlet passageways 20. This will permit the air to escape very slowlyand the brakes will therefore be slowly released.

The plug 12 can be adjusted to vary the tension of the spring 15 andhave the piston 10 operate at diii erent pressures. If the pressurewithin the brake cylinder exceeds the force exerted by the spring 15,the air will quickly drive the piston toward the plug 12, thuspermitting the air to quickly exhaust from the. cylinder until thepressure within the cylinder balances the force out through thepassageways 20 and the passageways 21 and 22.

It should be noted that one of the outstanding i eatures of my inventionover the ordinary type of retaining valve, is that it is-automa'tie inoperation and that it is selfcleaning. It is practically impossible toplug up the passages 20, 22 or 23 since sand or any substances admittedto the passages will be blown out upqn the first actuation of thedevice.

I claim: 1. An automat c pressure retaining valve of the characterdescribed comprising a tubular body member, a piston valve closelyfitted within said body member and adapted for longitudinal movementtherein, means for connectmg the interior of said body member with theexhaust port of a standard *triple valve for railroad air brakes, and a.plurality of exhaust ports through said body member, certain of whichare closed by said :piston valve when at one end of its travel-and whichare open when the piston valve 1S moved as loy-alr pressure from saidexhaust.

2. An automatic pressure retaining valve of the character describedcomprising a tubular body member, a piston valve closely fitted withinsaid body member and adapted for longitudinal movement therein, meansfor connecting the interior of said body member with the exhaust port ofa standard triple valve for railroad air brakes, a plurality of exhaustports through said body member, certain of which are closed by saidpiston valve when at one end of its travel and which are open when thepiston valve is moved as by air pressure from said exhaust, and a springfor yieldingly holding said piston valve in a position to close certainof said vents.

3. An automatic pressure retaining valve of the character describedcomprising a tubular body member, a piston valve closely fitted withinsaid body member and adapted for longitudinal movement therein, meansfor connecting the interior of said body member with the exhaust port ofa standard triple valve for railroad air brakes, a plurality of exhaustports through said body member, certain of which are closed bysaidpiston valve when at one end of its travel and which are open when thepiston valve is moved as by air pressure from said exhaust, a spring foryieldingly holding said piston valve in a position to close certain ofsaid Vents, and means for adjusting the compression of said spring atwill.

4. The combination with an exhaust port of a standard triple valve forrailroad air brakes, of automatic means for impeding the exhaust of airthrough said exhaust port, whereby the air may exhaust slowly, saidmeans being constructed so as to permit the unobstructed exhaust of airwhen i the pressure of the air exceeds a predetermined degree.

5. The combination with a brake cylinder having an exhaust port, ofmeans attached to said exhaust port for causing the air to exhaustslowly from the port, said means being entirely controlled by theexhaust air, and means for permitting the quick exhaust of air when thepressure exceeds a predetermined point, and for slowly exhausting theremaining air after the pressure has dropped down to the predeterminedpoint.

6. The combination with a brake cylinder having an exhaust port, ofmeans attached to said exhaust port for causing the air to exhaustslowly from the port, said means being entirely controlled by theexhaust air, and means for permitting the quick exhaust of air when thepressure exceeds a predetermined point, and for slowly exhausting theremaining air after the pressure has dropped down to the predeterminedpoint, said last named means being adjustable for various pressures.

7. The combination with a brake cylinder having an exhaust port, of acasing removably secured to said exhaust port, a

piston slidably mounted in said casing, a

spring means for seating said piston, said piston having grooves thereinto permit the slow exhaust of air when said piston is seated, saidcasing having air outlet open: ings adapted to be uncovered by the movment of said piston, said springs being adjustable to cause the pistonto move at various pressures and to again seat'when this pressure hasbeen reached.

JOHN LEO FARMER.

